/*

  sftp_util.c 

  Author: Pekka Riikonen <priikone@silcnet.org>

  Copyright (C) 2001 Pekka Riikonen

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; version 2 of the License.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

*/

#include "silcincludes.h"
#include "silcsftp.h"
#include "sftp_util.h"

/* Encodes a SFTP packet of type `packet' of length `len'. The variable
   argument list is encoded as data payload to the buffer. Returns the
   encoded packet or NULL on error. The caller must free the returned
   buffer. */

SilcBuffer silc_sftp_packet_encode(SilcSFTPPacket packet, uint32 len, ...)
{
  SilcBuffer buffer;
  va_list vp;

  va_start(vp, len);
  buffer = silc_sftp_packet_encode_vp(packet, len, vp);
  va_end(vp);

  return buffer;
}

/* Same as silc_sftp_packet_encode but takes the variable argument list
   pointer as argument. */

SilcBuffer silc_sftp_packet_encode_vp(SilcSFTPPacket packet, uint32 len, 
				      va_list vp)
{
  SilcBuffer buffer;
  int ret;

  buffer = silc_buffer_alloc(4 + 1 + len);
  silc_buffer_pull_tail(buffer, SILC_BUFFER_END(buffer));
  silc_buffer_format(buffer, 
		     SILC_STR_UI_INT(len),
		     SILC_STR_UI_CHAR(packet),
		     SILC_STR_END);
  silc_buffer_pull(buffer, 5);

  ret = silc_buffer_format_vp(buffer, vp);
  if (ret < 0) {
    silc_buffer_free(buffer);
    return NULL;
  }

  silc_buffer_push(buffer, 5);

  return buffer;
}

/* Decodes the SFTP packet data `packet' and return the SFTP packet type.
   The payload of the packet is returned to the `payload' pointer. Returns
   0 if error occurred during decoding. */

SilcSFTPPacket silc_sftp_packet_decode(SilcBuffer packet,
				       unsigned char **payload,
				       uint32 *payload_len)
{
  uint32 len;
  uint8 type;
  int ret;

  ret = silc_buffer_unformat(packet,
			     SILC_STR_UI_INT(&len),
			     SILC_STR_UI_CHAR(&type),
			     SILC_STR_END);
  if (ret < 0)
    return 0;

  if (type < SILC_SFTP_INIT || type > SILC_SFTP_EXTENDED_REPLY)
    return 0;

  if (len > (packet->len - 5))
    return 0;

  silc_buffer_pull(packet, 5);
  ret = silc_buffer_unformat(packet, 
			     SILC_STR_UI_XNSTRING(payload, len),
			     SILC_STR_END);
  if (ret < 0)
    return 0;

  silc_buffer_push(packet, 5);

  *payload_len = len;

  return (SilcSFTPPacket)type;
}

/* Encodes the SFTP attributes to a buffer and returns the allocated buffer.
   The caller must free the buffer. */

SilcBuffer silc_sftp_attr_encode(SilcSFTPAttributes attr)
{
  SilcBuffer buffer;
  int i, ret, len = 4;

  if (attr->flags & SILC_SFTP_ATTR_SIZE)
    len += 8;
  if (attr->flags & SILC_SFTP_ATTR_UIDGID)
    len += 8;
  if (attr->flags & SILC_SFTP_ATTR_PERMISSIONS)
    len += 4;
  if (attr->flags & SILC_SFTP_ATTR_ACMODTIME)
    len += 8;
  if (attr->flags & SILC_SFTP_ATTR_EXTENDED) {
    len += 4;
    for (i = 0; i < attr->extended_count; i++) {
      len += 8;
      len += attr->extended_type[i]->len;
      len += attr->extended_data[i]->len;
    }
  }

  buffer = silc_buffer_alloc(len);
  silc_buffer_pull_tail(buffer, SILC_BUFFER_END(buffer));

  silc_buffer_format(buffer, 
		     SILC_STR_UI_INT(attr->flags), 
		     SILC_STR_END);
  silc_buffer_pull(buffer, 4);

  if (attr->flags & SILC_SFTP_ATTR_SIZE) {
    silc_buffer_format(buffer, 
		       SILC_STR_UI_INT64(attr->size), 
		       SILC_STR_END);
    silc_buffer_pull(buffer, 8);
  }

  if (attr->flags & SILC_SFTP_ATTR_UIDGID) {
    silc_buffer_format(buffer, 
		       SILC_STR_UI_INT(attr->uid), 
		       SILC_STR_UI_INT(attr->gid), 
		       SILC_STR_END);
    silc_buffer_pull(buffer, 8);
  }

  if (attr->flags & SILC_SFTP_ATTR_PERMISSIONS) {
    silc_buffer_format(buffer, 
		       SILC_STR_UI_INT(attr->permissions), 
		       SILC_STR_END);
    silc_buffer_pull(buffer, 4);
  }

  if (attr->flags & SILC_SFTP_ATTR_ACMODTIME) {
    silc_buffer_format(buffer, 
		       SILC_STR_UI_INT(attr->atime), 
		       SILC_STR_UI_INT(attr->mtime), 
		       SILC_STR_END);
    silc_buffer_pull(buffer, 8);
  }

  if (attr->flags & SILC_SFTP_ATTR_EXTENDED) {
    silc_buffer_format(buffer, 
		       SILC_STR_UI_INT(attr->extended_count), 
		       SILC_STR_END);
    silc_buffer_pull(buffer, 4);

    for (i = 0; i < attr->extended_count; i++) {
      ret = 
	silc_buffer_format(buffer, 
			   SILC_STR_UI_INT(attr->extended_type[i]->len),
			   SILC_STR_UI_XNSTRING(attr->extended_type[i]->data,
						attr->extended_type[i]->len),
			   SILC_STR_UI_INT(attr->extended_data[i]->len),
			   SILC_STR_UI_XNSTRING(attr->extended_data[i]->data,
						attr->extended_data[i]->len),
			   SILC_STR_END);
      silc_buffer_pull(buffer, ret);
    }
  }

  silc_buffer_push(buffer, buffer->data - buffer->head);

  return buffer;
}

/* Decodes SilcSFTPAttributes from the buffer `buffer'. Returns the allocated
   attributes that the caller must free or NULL on error. */

SilcSFTPAttributes silc_sftp_attr_decode(SilcBuffer buffer)
{
  SilcSFTPAttributes attr;

  attr = silc_calloc(1, sizeof(*attr));

  if (silc_buffer_unformat(buffer, 
			   SILC_STR_UI_INT(&attr->flags), 
			   SILC_STR_END) < 0)
    goto out;

  silc_buffer_pull(buffer, 4);

  if (attr->flags & SILC_SFTP_ATTR_SIZE) {
    if (silc_buffer_unformat(buffer, 
			     SILC_STR_UI_INT64(&attr->size), 
			     SILC_STR_END) < 0)
      goto out;

    silc_buffer_pull(buffer, 8);
  }

  if (attr->flags & SILC_SFTP_ATTR_UIDGID) {
    if (silc_buffer_unformat(buffer, 
			     SILC_STR_UI_INT(&attr->uid), 
			     SILC_STR_UI_INT(&attr->gid), 
			     SILC_STR_END) < 0)
      goto out;

    silc_buffer_pull(buffer, 8);
  }

  if (attr->flags & SILC_SFTP_ATTR_PERMISSIONS) {
    if (silc_buffer_unformat(buffer, 
			     SILC_STR_UI_INT(&attr->permissions), 
			     SILC_STR_END) < 0)
      goto out;

    silc_buffer_pull(buffer, 4);
  }

  if (attr->flags & SILC_SFTP_ATTR_ACMODTIME) {
    if (silc_buffer_unformat(buffer, 
			     SILC_STR_UI_INT(&attr->atime), 
			     SILC_STR_UI_INT(&attr->mtime), 
			     SILC_STR_END) < 0)
      goto out;

    silc_buffer_pull(buffer, 8);
  }

  if (attr->flags & SILC_SFTP_ATTR_EXTENDED) {
    int i;

    if (silc_buffer_unformat(buffer, 
			     SILC_STR_UI_INT(&attr->extended_count), 
			     SILC_STR_END) < 0)
      goto out;

    silc_buffer_pull(buffer, 4);

    attr->extended_type = silc_calloc(attr->extended_count, 
				      sizeof(*attr->extended_type));
    attr->extended_data = silc_calloc(attr->extended_count, 
				      sizeof(*attr->extended_data));
    for (i = 0; i < attr->extended_count; i++) {
      unsigned char *tmp, *tmp2;
      uint32 tmp_len, tmp2_len;

      if (silc_buffer_unformat(buffer, 
			       SILC_STR_UI32_NSTRING(&tmp, &tmp_len),
			       SILC_STR_UI32_NSTRING(&tmp2, &tmp2_len),
			       SILC_STR_END) < 0)
	goto out;

      attr->extended_type[i] = silc_buffer_alloc(tmp_len);
      attr->extended_data[i] = silc_buffer_alloc(tmp2_len);
      silc_buffer_put(attr->extended_type[i], tmp, tmp_len);
      silc_buffer_put(attr->extended_data[i], tmp2, tmp2_len);

      silc_buffer_pull(buffer, tmp_len + 4 + tmp2_len + 4);
    }
  }

  return attr;

 out:
  silc_sftp_attr_free(attr);
  return NULL;
}

/* Frees the attributes context and its internals. */

void silc_sftp_attr_free(SilcSFTPAttributes attr)
{
  int i;

  for (i = 0; i < attr->extended_count; i++) {
    silc_buffer_free(attr->extended_type[i]);
    silc_buffer_free(attr->extended_data[i]);
  }
  silc_free(attr->extended_type);
  silc_free(attr->extended_data);
  silc_free(attr);
}

/* Adds an entry to the `name' context. */

void silc_sftp_name_add(SilcSFTPName name, const char *short_name,
			const char *long_name, SilcSFTPAttributes attrs)
{
  name->filename = silc_realloc(name->filename, sizeof(*name->filename) *
				(name->count + 1));
  name->long_filename = silc_realloc(name->long_filename, 
				     sizeof(*name->long_filename) *
				     (name->count + 1));
  name->attrs = silc_realloc(name->attrs, sizeof(*name->attrs) *
			     (name->count + 1));

  name->filename[name->count] = strdup(short_name);
  name->long_filename[name->count] = strdup(long_name);
  name->attrs[name->count] = attrs;
  name->count++;
}

/* Encodes the SilcSFTPName to a buffer and returns the allocated buffer. 
   The caller must free the buffer. */

SilcBuffer silc_sftp_name_encode(SilcSFTPName name)
{
  SilcBuffer buffer;
  int i, len = 4;
  SilcBuffer *attr_buf;

  attr_buf = silc_calloc(name->count, sizeof(*attr_buf));
  for (i = 0; i < name->count; i++) {
    len += (8 + strlen(name->filename[i]) + strlen(name->long_filename[i]));
    attr_buf[i] = silc_sftp_attr_encode(name->attrs[i]);
    len += attr_buf[i]->len;
  }

  buffer = silc_buffer_alloc(len);
  silc_buffer_pull_tail(buffer, SILC_BUFFER_END(buffer));

  silc_buffer_format(buffer,
		     SILC_STR_UI_INT(name->count),
		     SILC_STR_END);
  silc_buffer_pull(buffer, 4);

  for (i = 0; i < name->count; i++) {
    len =
      silc_buffer_format(buffer,
			 SILC_STR_UI_INT(strlen(name->filename[i])),
			 SILC_STR_UI32_STRING(name->filename[i]),
			 SILC_STR_UI_INT(strlen(name->long_filename[i])),
			 SILC_STR_UI32_STRING(name->long_filename[i]),
			 SILC_STR_UI_XNSTRING(attr_buf[i]->data,
					      attr_buf[i]->len),
			 SILC_STR_END);

    silc_buffer_pull(buffer, len);
    silc_free(attr_buf[i]);
  }
  silc_free(attr_buf);

  silc_buffer_push(buffer, buffer->data - buffer->head);

  return buffer;
}

/* Decodes a SilcSFTPName structure from the `buffer' that must include
   `count' many name, longname and attribute values. Returns the allocated
   structure or NULL on error. */

SilcSFTPName silc_sftp_name_decode(uint32 count, SilcBuffer buffer)
{
  SilcSFTPName name;
  int i;
  int ret;

  name = silc_calloc(1, sizeof(*name));
  name->filename = silc_calloc(count, sizeof(*name->filename));
  name->long_filename = silc_calloc(count, sizeof(*name->filename));
  name->attrs = silc_calloc(count, sizeof(*name->attrs));
  name->count = count;

  for (i = 0; i < count; i++) {
    ret = 
      silc_buffer_unformat(buffer,
			   SILC_STR_UI32_STRING_ALLOC(&name->filename[i]),
			   SILC_STR_UI32_STRING_ALLOC(&name->long_filename[i]),
			   SILC_STR_END);
    if (ret < 0) {
      silc_sftp_name_free(name);
      return NULL;
    }

    silc_buffer_pull(buffer, ret);

    /* Decode attributes, this will pull the `buffer' to correct place
       for next round automatically. */
    name->attrs[i] = silc_sftp_attr_decode(buffer);
  }

  return name;
}

/* Frees the name context and its internals. */

void silc_sftp_name_free(SilcSFTPName name)
{
  int i;

  for (i = 0; i < name->count; i++) {
    silc_free(name->filename[i]);
    silc_free(name->long_filename[i]);
    silc_sftp_attr_free(name->attrs[i]);
  }

  silc_free(name->filename);
  silc_free(name->long_filename);
  silc_free(name->attrs);
  silc_free(name);
}

/* Maps errno to SFTP status message. */

SilcSFTPStatus silc_sftp_map_errno(int err)
{
  SilcSFTPStatus ret;

  switch (err) {
  case 0:
    ret = SILC_SFTP_STATUS_OK;
    break;
  case ENOENT:
  case ENOTDIR:
  case EBADF:
  case ELOOP:
    ret = SILC_SFTP_STATUS_NO_SUCH_FILE;
    break;
  case EPERM:
  case EACCES:
  case EFAULT:
    ret = SILC_SFTP_STATUS_PERMISSION_DENIED;
    break;
  case ENAMETOOLONG:
  case EINVAL:
    ret = SILC_SFTP_STATUS_BAD_MESSAGE;
    break;
  default:
    ret = SILC_SFTP_STATUS_FAILURE;
    break;
  }

  return ret;
}